This invention relates to a structure composed of at least two structural elements joined together by connection means. Particularly, but not exclusively, the said structure could be the framework of a motor vehicle, such as a motor bus, and the structural elements could conveniently be section bars. In general, a so-called "force" connection, i.e. able to withstand considerable mechanical stresses, is currently made by welding. Although this connection method is widely used, it has certain drawbacks. In this respect, from the environmental viewpoint noise, smoke and sparks are produced requiring special precautions to be taken to protect the operator. If the elements to be welded together have already undergone initial painting (for example rust protection), the paint has obviously to be removed from the zone to be welded, and this can subsequently easily trigger rust formation. Welding also requires certain subsequent work to be carried out, such as grinding, hammering and filling of the welded zones. It is also not possible to weld incompatible materials together such as a light alloy to stainless steel or aluminium etc. From the operational viewpoint, making a plurality of welds within a large-dimension structure, such as that of a motor bus, obviously leads to problems in handling the welding heads. In the specific case of motor bus structures assembled by welding, it has been noted that further drawbacks arise each as poor production flexibility if modifications have to be made to portions of the structure which have already been prewelded, the need to keep numerous different configurations of prewelded parts of the structure in stock in order to rapidly satisfy the constructional requirements of a motor bus, and difficulty in the construction and handling of structure portions which, because of progressive welding, increase in dimensions and space requirements as assembly proceeds.